1. Field of the Invention
The present invention relates to a mobile communication system. More particularly, the present invention relates to an in-device coexistence interference report control method of a network in a mobile communication system, the in-device coexistence interference being reported by the terminal to inform the network of interference among heterogeneous radio communication modules coexisting in the terminal.
2. Description of the Related Art
With rapid advances in radio communication technology, the communication system has evolved to meet the requirements of 4th Generation (4G) mobile communication technology such as Long Term Evolution (LTE).
The widespread use of smartphones has increased demand for supplementary wireless technologies such as Wireless Local Area Network (WLAN), Bluetooth, and Global Positioning System (GPS). In order to meet this demand, several communication technologies (e.g., cellular technology (LTE/UMTS), WLAN, Bluetooth, and GNSS/GPS) are being integrated into a single portable device. As a consequence, inter-technology interference problem is emerging as a key issue to be solved. This issue is under discussion in the name of In-Device Coexistence (IDC) in the 3rd Generation Partnership Project (3GPP).
The LTE/UMTS communication technology operates on various frequency bands while the Bluetooth and WLAN operate on the Industrial, Scientific and Medical (ISM) band of 2400˜2483.5 MHz. Among the frequency bands assigned for the LTE/UMTS communication, Band 4 (2300˜2400 MHz) and Band 7 uplink (2500˜2670 MHz) are close to the ISM band used by Bluetooth and WLAN such that the simultaneous operations of the two technology modules cause significant interference to each other, e.g. a signal transmitted by one communication technology module may be received by the other communication technology module in the same device.
This interference can be mitigated in such a way that the terminal reports the interference to the network and thus the network commands handover of the terminal to use another frequency. However, if the network does not understand the interference report message, this means that the terminal transmits the interference report message uselessly, resulting in increase of unnecessary signaling. There is therefore a need of a method to address this issue.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present invention.